It is known to measure the level of a liquid inside of a container by the use of reed switches which are actuated by a float containing permanent magnets. For example, U.S. Pat. Nos. 3,473,381 and 3,678,750 disclose an array of magnetic reed switches which are actuated by a float for switching resistances.
The present invention is directed to an improved reed switch liquid level measuring apparatus which avoids temperature sensitive resistors and is not affected by temperature, Pressure or depth. The reed switches and magnetic field are positioned and oriented to provide an increased resolution. The apparatus provides a digital readout with a low current which makes it suitable for applications in explosive environments, and current drain is avoided between measurements.